/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.zookeeper.server.quorum;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.zookeeper.server.Request;
import org.apache.zookeeper.server.RequestProcessor;
import org.apache.zookeeper.server.SyncRequestProcessor;
import org.apache.zookeeper.server.ZooKeeperServer;

/**
 * This RequestProcessor simply forwards requests to an AckRequestProcessor and
 * SyncRequestProcessor.
 */
public class ProposalRequestProcessor implements RequestProcessor {
	private static final Logger LOG = LoggerFactory.getLogger(ProposalRequestProcessor.class);

	RequestProcessor nextProcessor;

	SyncRequestProcessor syncProcessor;

	LeaderZooKeeperServer zks;

	public ProposalRequestProcessor(LeaderZooKeeperServer zks, RequestProcessor nextProcessor) {
		this.zks = zks;
		this.nextProcessor = nextProcessor;
		AckRequestProcessor ackProcessor = new AckRequestProcessor(zks.getLeader());
		syncProcessor = new SyncRequestProcessor(zks, ackProcessor);
	}

	/**
	 * initialize this processor
	 */
	public void initialize() {
		syncProcessor.start();
	}

	public void processRequest(Request request) {
		// LOG.warn("Ack>>> cxid = " + request.cxid + " type = " +
		// request.type + " id = " + request.sessionId);
		// request.addRQRec(">prop");

		/*
		 * In the following IF-THEN-ELSE block, we process syncs on the leader. If the
		 * sync is coming from a follower, then the follower handler adds it to
		 * syncHandler. Otherwise, if it is a client of the leader that issued the sync
		 * command, then syncHandler won't contain the handler. In this case, we add it
		 * to syncHandler, and call processRequest on the next processor.
		 */

		if (request instanceof LearnerSyncRequest) {
			zks.getLeader().processSync((LearnerSyncRequest) request);
		} else {
			nextProcessor.processRequest(request);
			if (request.hdr != null) {
				// We need to sync and get consensus on any transactions
				zks.getLeader().propose(request);
				syncProcessor.processRequest(request);
			}
		}
	}

	public void shutdown() {
		LOG.info("Shutting down");
		nextProcessor.shutdown();
		syncProcessor.shutdown();
	}

}
